The Herald. August 6, 2014.

If the long argument over independence has had a sub-text, it has been the demand for information. To hear it told, there's a national shortage. Nervous voters are being asked to make their leaps into the forbidding dark without so much as a few flimsy parachutes of facts.

So the No side would have it, at any rate. Yet where the future is concerned they don't stock many facts themselves because that is not, it seems, their job. Will David Cameron and Nick Clegg be offering another coalition if we vote No? Will Scotland remain in membership of the European Union beyond 2017? Which coalition deeds – which deeds specifically – will be undone if Ed Miliband wins office?

No one is asking for long-range forecasts. Next year, the year after: those would do. The inquiry under the heading “information” is simplicity itself: what happens if we vote No? A few rough guesses might be sufficient. Scottish voters are sophisticated enough to work through the permutations.

Instead, Unionist crystal balls have become a little cloudy this summer. Even the brave claim that we are better together with Britain thanks to “strength” and “stability” doesn't do well under scrutiny. Which Britain? The one that bears the stamp of Mr Cameron, or the one on which Mr Miliband would like to impress himself? Are they one and the same? Are they close copies of the Britain in which we live now? Any clues?

It amounts to a bit of an oversight. If no one should dare to vote Yes without an arsenal of facts to cover every eventuality for the next few decades – such is the customary demand – then No campaigners should be eager, not to say proud, to fight an information war. Yet each time the invitation has been extended, No Thanks has been the answer.

All of a sudden, things have changed, supposedly. All of a sudden, guarantees are flying around. By sheer coincidence, by a mere fluke, leaders of the Westminster parties yesterday chose the eve of a TV debate between Alex Salmond and Alistair Darling to make a solemn promise, a pledge good for all electoral eventualities. Parties that saw no need to offer Scotland anything much until the referendum was upon them are in the words and bonds business.

There are promises, in short, of more powers. First, note the plurals. Tories, Labour and the Liberal Democrats each have something different in mind. So which would be your reward for voting No? We'll come to that.

There are several rounds to this beauty contest. First you have to reject independence. Then you have to decide that two of the three definitions of “more powers” aren't worth your attention. Then you have to vote for the party with the offer you might be looking for. Then you have to hope your tribunes can either win a general election, or maintain the grand pledge amid the horse-trading and bad faith of coalition negotiations. It really is that simple.

Well, not so simple. You also have to stop thinking from now until September 18. Your mind has to be cleansed of unworthy thoughts, thoughts such as “If Mr Cameron is now making noises akin to a devo-max deal, why did he insist, with acquiescence of the other two, that such a deal should on no account be on the ballot paper?” If the opinion polls were accurate, “more powers” was the dearest wish of the greatest number of Scots. Yet the Prime Minister wouldn't have it.

Now the Three Amigos, with Mr Cameron at their head, produce a declaration worth almost as much as the paper it is written on, stating that “We support a strong Scottish Parliament in a strong United Kingdom and we support the further strengthening of the parliament's powers”. This, it seems, means “fiscal responsibility and social security”.

They can give you no more information than that. Where your future is concerned, they're short on facts. They are short on agreement, indeed, as to what might be best for Scotland, its parliament, or relations with the rest of the United Kingdom. “Powers” has a lovely ring, even if the word points to the tiny flaw in all those polls demonstrating the popularity of devo-max.

It transpired that a fair number of those voicing support for the proposition didn't know which powers they meant, or which powers were already devolved to Edinburgh. Once, Unionists loved to point out these supposed facts. Now, given the risks posed by the straight choice Mr Cameron himself demanded, the very vagueness of devo-mmax is part of its attraction.

What's (slightly) fascinating is the way in which the Unionist camp uses the phrase “more powers”. The nature of the powers is all but irrelevant: the three men can't agree, won't agree, and have no intention of attempting to agree on that. Only the fact-free incantation counts. You will be guaranteed “more powers”, of some unspecified description, and surely that's good enough? The powers themselves needn't matter, only the fact that there will be more of them. Probably.

If any of this counts as factual information of the kind so often demanded of the Yes campaign the bar is set lower than anyone realised. Would Mr Cameron support Mr Miliband's scheme if Labour happens to win a UK general election? In an finely-balanced Westminster would Labour vote through a Tory scheme that ran counter to its own proposals? Are we supposed to just put such thoughts from our minds and take a punt on the word “more”?

There's little point in saying that all of this fails to satisfy a claim for a properly representative parliament with all the powers it might need to do the job. The men from Westminster understand that perfectly well. The idea is to render Scotland quiescent and preserve the essence of its present relationship with the UK. There is no serious joint attempt to analyse that relationship – hence the lack of agreement – or improve governance. The declaration is a gesture, a spoiler, a distraction.

You could draw conclusions from that sort of fact. “Fiscal responsibility and social security” might sound nicely vague amid a referendum campaign. How do changes in those areas – any changes – sit with Westminster's aspirations for a unified tax and benefit systems? What becomes of the universal credit abomination? What kind of devolution is it that involves chipping some bits and pieces from central government's responsibilities without a thought for the wider UK consequences?

There is little evidence of logic in any of this. The three party leaders might have asked themselves about the powers that should not be granted to Edinburgh, for example, rather than fiddling around with the measures – the unspecified measures – that might be doled out one day. Instead, they are content to rely on the supposedly hypnotic effect of the word “powers”. They might as well be waving shiny trinkets in front of the voters.

That would be the general idea, of course: trust us and we'll give you something for your trouble. After all, it's a fact, isn't it, that these are three deeply trustworthy men who never break their words?